The invention relates to methods for bleaching teeth and the devices and substances used to perform such methods. More particularly, the invention relates to a more efficient, less expensive and less time consuming method for bleaching teeth that uses a formable substance to directly construct a dental bleaching tray rather than following the prior art steps of taking a dental impression, using the dental impression to form a mold, and using the mold to form a dental bleaching tray.
Dental bleaching is a well-known and economically important field. Increasingly, people are more concerned with maintaining an attractive personal appearance, and maintaining their teeth in good condition is critical to personal appearance. Of special importance is the color of a person""s teeth. Various foods such as juices, coffee and tea cause discoloration or staining of human teeth. Other habits, such as smoking or chewing tobacco also cause tooth discoloration. Therefore it has become important in our society to address tooth discoloration issues by a process of dental bleaching.
In the prior art, dental bleaching was accomplished by obtaining a dental bleaching tray, placing a dental bleach such as carbamide peroxide or hydrogen peroxide into the tray, placing the dental bleaching tray over teeth so that the dental bleach contacts the teeth, and permitting the dental bleaching tray to remain in place for a desired period of time, such as 1 to 8 hours, while bleaching takes place. Sometimes the prior art used a light source or a heat source to accelerate bleaching.
The prior art dental bleaching trays were constructed according to a complex, time consuming and expensive multi-step process. A person desiring to whiten his or her teeth would make an appointment with a dental care provider. The dental care provider, after examining the patient""s teeth, would take an impression of the patient""s teeth using known dental impression materials, such as alginate. The dental impression materials were displaced by the patient""s teeth and gums to form an accurate impression. It is well known that dental impressions can cause the patient discomfort and even pain.
After the dental impression was made, it was permitted to fully harden and was then transported to a dental laboratory. In the dental laboratory, a dental technician filled the dental impression with an appropriate mold making material such as stone gypsum. The mold making material would conform to the shape of the dental impression to accurately duplicate the shape of the patient""s teeth and gums. Once hardened, the mold making material formed a mold of the patient""s teeth and gums.
The mold was then placed onto a vacuum former adjacent a sheet of plastic. Under heat and vacuum, the plastic sheet closely adhered to the mold to form a dental bleaching tray that closely conformed to the patient""s teeth and gums. The formed dental bleaching tray was then removed from the vacuum former and any excess plastic was trimmed from it. It was then transported to the dental care provider""s office. At a mutually convenient date, the dental care provider would schedule another appointment with the patient and verify or adjust fit of the dental bleaching tray. Thereafter, the dental bleaching tray could be used for dental bleaching performed by the patient at home or performed by the dental care provider in his or her office.
From the above description, it can be seen that the process of forming a dental bleaching tray was very time consuming, labor intensive and expensive, requiring at least two visits to the dental care provider""s office by the patient and work by a dental laboratory technician. Typically at least two weeks would pass between the patient""s request for a dental bleaching tray and its delivery to the patient.
There is a demand for dental bleaching trays which can be fabricated immediately by a dental care provider or a patient without the use of a dental laboratory or a dental laboratory technician, and that do not include the great amounts of time and labor that the prior art processes require.
It is an object of the invention to provide a method by which a dental bleaching tray may be formed directly by impressing a person""s teeth into a moldable material without intermediate mold forming and molding steps as seen in the prior art.
Additional objects, features and advantages of the invention will become apparent to the reader on reading the patent specification in light of the appended drawings.